1. Field of the Invention
The present invention relates to a photographic camera.
2. Description of the Prior Art
A camera which can have its shape changed depending on a time of use and a time when not in not in use, for example a camera, in which a front housing containing a photographic optical system, an exposure device, etc. and a rear housing containing photosensitive material for exposure and a finder optical system are coupled together by a foldable coupling device such as a bellows, etc., and the coupling device is extended to bring the distance between the front housing and the rear housing to such a length as suitable for photographing, and wherein the coupling device is collapsed when photographing is not performed so as to have the front housing and the rear housing located very close to each other in order to make a camera compact for carrying, has been proposed heretofore in many ways.
A camera of this type, for example, uses a photosensitive sheet material of self-developing type, a so-called "instant picture camera". The photosensitive sheet material of a self-developing type can be found for example in the specification of U.S. Pat. No. 3,682,076. Such photosensitive sheet material of self-developing type disclosed in this U.S. Pat. No. 3,682,076 has a bag storing self-developer process liquid within the material, and the bag storing the developer liquid is broken when said material is carried outside of the camera through a pair of pressure contacting rollers provided at a photosensitive material carry-out device within the camera after exposure. Developer process liquid flowing out of the bag is spread over a photosensitive surface of the photosensitive sheet material, thus conducting self-developing process. The photosensitive sheet material is housed in a film cassette with a plural number of sheets being analyzed. The camera is loaded when a cassette with a photosensitive sheet material is placed into the rear housing. This photosensitive sheet material of self-developing process type does not employ a method for making only a negative image on the photosensitive material and making a position image on another photographic paper enlarging the negative image like a photosensitive material used in an ordinary camera. Instead a positive image is formed in its actual size on an exposure surface being exposed without being enlarged and it is so viewed and appreciated. Thus if a size of a photosensitive surface is too small it is rather difficult to appreciate. Therefore, the size of photosensitive sheet material of self-developing process type is much larger than that of a roll film of 35-mm size. Thus the shape of an instant picture camera is much larger than that of an ordinary camera using a roll film of 35-mm size, resulting in poor portability.
Because of this reason, and in order to improve portability even to a limited extent especially in an instant picture camera, a front housing containing a photographic optical system, an exposure device, etc. and a rear housing containing a photographic sheet material, a finder optical system, etc. are coupled by a foldable coupling device such as a bellows, etc., and said coupling device is extended as photographing is done to bring the distance between the front housing and the rear housing to a length suitable for photographing, while the coupling device is collapsed when photographing is not done to have the front housing and the rear housing come very close to each other. This assures compactness when the camera is carried.
While photosensitive material is emitted from an exit of the camera to outside of the camera by pressure rollers provided at a photosensitive material emission device within the camera after exposure in this kind of instant picture camera, the distance between the pressure contacting rollers and the outlet for carrying out photosensitive material in this instant picture camera is sufficiently provided. The reason therefor is that a bag storing self-developer process liquid is provided within the photosensitive material and the bag containing developer process liquid is broken as it passes between a pair of pressure contacting rollers provided at the photosensitive material carry-out device within the camera after exposure. The developer liquid flowing out of the bag is spread by the pressure contacting rollers for conducting self-developing process. Further it takes some time until said developer liquid covers entire photosensitive surface. If external light hits the exposed photosensitive surface before the developer liquid covers the entire photosensitive surface, the finished picture is adverse affected. Therefore, to prevent external light from hitting the photosensitive surface before the developer liquid covers the entire photosensitive surface, the distance between the pressure contacting rollers and the photosensitive material carryout outlet is sufficiently large so that enough time for the developer liquid to cover the entire photosensitive surface.
Also, in a camera having a finder window and a range finding window provided therein as in an instant picture camera and also in a single lens reflex camera especially, a finder window and a range finder window are provided at a front plane of a camera, and these windows are covered with glass plates. Difficulties sometimes occur in this kind of camera when the glass planes are stained upon being touched by a stained hand when the camera is carried without being placed in a camera case or when the glass plates are damaged as the camera is hit by some object.